Light projector



Feb. 19, 1935. I v RQPEYR ET AL 1,992,041

LIGHT PROJECTOR Filed Aug. 16, 1932 INVENTURE: 1/2552. 1/. RUPEA mLLARDCIEmI Ym 1 2221a. .42" TDELNE Y Patented Feb. 19, 1935 i i I UNITED STATES PATENT OFFICE LIGHT PROJECTOR Val J. Roper, Cleveland, and Willard C. Brown, East Cleveland, Ohio, assignors to General Electric Company, a corporation .of New York Application August 16, 1932, Serial No. 629,010

1 Claim. (Cl. 240-41) Our invention relates to light projectors which lowered wind resistance and better appearance comprise a reflector and a light source accuratearising from the use of smaller headlamps. With ly disposed with reference to the surface of the such reflectors, single filament lamps may be used said reflector. Such reflectors may be in the to better advantage than at present as more form of a surface of revolution such as a parabheadlamps may be employed. Another object 5 oloid, and with at least one focus; or they may ofour invention is the provision of a device which have modified contour with an equivalent focus may comprise a small reflector with the position or with an optimum point for the light source. of the light source fixed so accurately that a In order to obtain dependable results, the light beam of the correct dimensions and directions source must be accurately located with reference may always be secured.

to the said focus or optimum point. More espe- According to our invention the reflector and cially our invention relates to ordinary vehicle electric lamp are fixedly united and in the procheadlamps. According to the prevailing practice ess of their union the position of the light source such headlamps comprise a parabolic reflector or is so fixed with reference to the reflector that modified parabolic reflector and a socket which a beam of the desired illumination and distribu- 15 received an incandescent electric lamp. Accordtion is uniformly secured. The preferred form ing to one practice, the socket is adjustable along of our invention is that in which a portion of the the longitudinal axis of the reflector, and accordreflector constitutes the base of the electric lamp. ing to another practice, the socket is fixed with, Other features and advantages of our invention reference to the reflector. In both cases, howwill appear from the following description there- 20 ever, the incandescent lamp is removable. In of and from the accompanying drawing. the former case reliance is placed upon the ad- In the drawing Fig. 1 is a horizontal section justment of the position of the socket and therethrough a reflector unit of our invention; Fig. 2 fore of thelamp filament preliminarily by the is a perspective diagrammatic view of apparatus manufacturer, and afterwards by the user of the employed in a method of definitely positioning 25 car. In the latter case there is no opportunity an electric lamp in a reflector; Fig. 3 is a vertical for adjustment after the manufacture of the section of a projector utilizing two reflector units headlamp, and reliance is placed upon the uniof our invention; Fig. 4 is a horizontal sectional formity of the incandescent lamp filament posiview of a modification of said unit; and Fig. 5 is tionillg y t incandescent a p ma u acturer, a vertical section through a projector utilizing 30 and also of course upon the accurate positioning said modification.

of the socket with reference to the reflector by Referring now to the drawing and more parthe headlamp manufacturer. One object of our ticularly to Fig. 1 thereof, our inventon comprises invention is to provide means of securing more a reflector 10, in this instance having a parabolic dependable results and to provide an effective contour, withaflang 11 extending Outward from 35 and eflicient method of manufacture of the dethe rim thereof and with an opening at the apex Vice Securing S es t thereof in which is mounted an incandescent Heretofore the filament has not always been lamp 12. The lam 12 is supported in the desired positioned with reference to the focus of the relocation by a ring 13 of cement in a heel 14 ex- 0 fiector due either to inaccuracies of assembly of tending rearwardly of the reflector. The cement the socket with the reflector or, in some cases, to adheres to the inner surface of said heel and to variations in position of the filament with referthe neck 15 of the lamp bulb. The said heel is ence to the base which is received in the socket. preferably flrnily attached to the back of the re Inasmuch asthe larger reflectors with the longer flector by soldering or welding and supports by focal distances are less sensitive to inaccurate an inwardly extending flange an insulating plug 45 filament positioning, the tendency has been to 16 through which conductors 1'1 and 18 pass. make use of the larger reflectors. There are, Conductor 17 is attached within the shell to lead however, advantages in the use of smaller rewire 19. The lead wires 18 and 19 pass inwardly flectors inasmuch as it enables the use of more through the stem press 20 into the interior of the reflector and light source combinations and their lamp 12 and are each connected to an end of the 50 effective disposition in the front of the vehicle. filament 21 mounted therein.

The increased flexibility in design gained by the We prefer to use the method indicated in Fig.

use of the smaller reflectors is important not 2 for the adjustment of the lamp with reference only from the standpoint of effective light distrito the reflector. This is performed while the cebution, but also because of such advantages as ment 13 is still in a plastic state. The method with a shield 22 having a plurality of apertures 23 therein which allow a series of images of the filament to be thrown on screen 24. As illustrated, a parabolic reflector is used and the shield has a pair of apertures horizontally disposed, as well as a pair vertically disposed. The screen is marked with figures, rectangles 24' as shown, one for each aperture in the shield 22. These indicate the tolerance allowable for inaccuracy of filament position when the screen is positioned a definite distance from the lamp. Should the filament be located incorrectly to the left or right, the horizontally disposed pair of images will be out of position and so also will the vertically disposed pair of images should the lamp require adjustment vertically. Incorrect location along the axis of the reflector, that is, when the filament is ahead or behind proper position, causes both the horizontal and vertical pairs of images to bek displaced. By suitably adjusting the position of the lamp, the images may be caused to fall each within the limits of a figure and the cement then allowed to harden. On account of the accuracy of this method it may be employed for very small reflectors of very short focal length which are exceptionally sensitive to improper fllamentposition.

An application in which two of the reflector units of our invention are used is shown in Fig. 3. In this instance two reflector units are used in order to produce beams of different elevation such as are at present used in automotive lighting. The reflector is in each case fastened immovably by flange 11 and screws (not shown) to the projector housing 25 and is covered by lens 26. The current is supplied to the lamps through cords 17 each comprising a pair of insulated conductors and connected to a plug 27 which is inserted in connecting block 28 attached to the housing. This is in turn connected to switching and battery equipment through 'cord 29.

The modification of our invention shown in Fig. 4 differs from the species just described in that the unit is constructed so as to be supported in the projector by heel 30. The heel is attached to the reflector 31 and cement 32 unites it to the neck of lamp bulb 33. The lamp filament 34 is definitely located with respect to the reflector and is connected to leading-in wires 35 and 36 which are in turn connected to the heel 30 and to conductive insert 37 in insulating plug 38 held therein. The said plug is located within the open end of the heel and forms part of the support for holding pins 39 which protrude laterally from the said heel. When used in a projector such as that shown in Fig. 5, the heel functions like a bayonet type lamp base as it fits snugly within the tubular portion 40 of a socket which carries the usual spring pressed contact pin (not shown) which engages center contact 37. The pins 39 engage bayonet slots 41 in the socket shell. The projector housing 42 supports the socket which connects to contacts carried by cap 43 connected to conductors in cord 44. The projector is also preferably covered by alens 45 which has an attaching ring 46.

What we claim as new and desire to secure by Letters Patent of the United States, is:

In a light projector, the combination of an electric lamp comprising a concentrated light source and an enclosing bulb, a reflector comprising a heel portion which is fixedly united to the neck of said bulb, and terminal connections supported by said heel portion, said light source being accurately located with reference to said reflector to produce a beam of desired dimensions and direction.

' VAL J. ROPER.

WILLARD C. BROWN. 

